Improvement in the mode of connecting the piston and pitman of steam-engines



R. s. EDWARDS.

improvement in the mode of Connecting the Piston and Pitman of' steam Engines.

No. 123,623. Pat e nted Feb. 13, 1872.

Wz'nesaea. Inventor. C. 6 am Maw-m4 e/Ytty,

j the pitman. jointed to the-longer arm of a lever, b, which,

RICHARD S. EDWARDS, OF SAVANNAH, MISSOURI.

IMPROVEMENT IN THE MODE OF CONNECTING THE PISTON AND PITMAN 0F STEAM-ENGINES.

Specification forming part of Letters Patent No. 123,623, dated February 13, 1872.

Specification describing certain Improvements in Apparatus for Connecting the Piston and Pitman of a Steam-Engine, invented by RICHARD S. EDWARDS, of Savannah, Andrew county, Missouri.

This invention relates to an apparatus to be interposed between the piston of a steam-engine and the pitman that would otherwise connect the piston with any piece of machinerya crank-pin, for instance-for the purpose of enabling the power to overcome a greater resistance than if connected directly with the pitman.

The figure is a side elevation.

Referring to the drawing, a is the piston, and The outer end of the piston is in common with the lever b, hereinafter mentioned,passes through slots formed lengthwise of the bars 0 (I, placed one above the other and supported by standards f. The fulcrum of the lever 12 is a pin, 0, connecting said lever with a bar, g, that slides in lugs h, springing from plates Z attachedto the upper side of the bar (1. Between lugs m, projecting upward from the same bar,is pivoted-a lever, n, whose lower extremity is connected by a link, 0,with one end or" the sliding-bar g. The upper extremity of the lever n, which is parallel with thelever b, is connected with the same by means of a horizontal link, 4. The lower endof the lever b is connected by a link, i, with the lower end of the parallel lever 1), whose fulcrum is apin, 6, connecting the lever 12 with a bar, 9, that slides in lugs h, springing from plates Z attached to the under side of the bar 0. Between lugs m,projecting downward from the same bar, is pivoted a lever, a, whose upper extremity is connected, by a link, 0, with one end of the sliding-bar g. The lower extremity of the lever a, which is parallel with the lever 71, is connected with the same by means of a horizontal link, 0. To the shorter arm of the lever 1) is jointed one end of the pitman j, whose other end may be jointed to the wrist-pin of a crank.

Inasmuch as the pitman j is connected with the shorter arm of the lever b while the piston to is connected with the longer arm of the lever 1) the pitman must movemore slowly than the piston. This retardation is augmented by making the levers b n, respectively, shorter than the levers b n, and still further increased by making the fulcrums e e sliding, owing to which arrangement the lower ends of the levers b b move more slowly than as though the fulcrums 0 were fixed. The upper end of the lever b is retarded in the same ratio as its lower end, and also moves more slowly than as though the fulcrums a were fixed. This loss in speed is compensated for by a gain in power, enabling the pitman to do more diflicult work than as though it were connected directly with the piston.

. I claim as my invention- The combination of the levers b b n a, connecting-rods t r r, and sliding-bars g g, with a suitable frame and supports, all arranged so as to forma connecting apparatus between the piston and pitman of a steam-engine, substantially as specified.

RICHARD S. EDWARDS.

Witnesses:

RANSOM SANBORN, SAMUEL 0. THOMPSON. 

